A recent study demonstrated that Kupffer cells could be recruited by the TCF4-CCL2-CCR2 signaling pathway, which is overexpressed in colorectal cancer and be polarized into M2, which can secrete pro-tumor cytokines such as IL-4, IL-13, VEGF and EGF to promote liver metastasis of colon cancer (84). Here, VEGFA is linked to colorectal cancer.